Up to now, Patent Document 1 discloses a depressurizing device that is applied to a vapor compression refrigeration cycle device, and depressurizes the refrigerant.
The depressurizing device of Patent Document 1 has a main body portion that defines a swirling space for swirling refrigerant, and allows refrigerant in a gas-liquid mixing state, which is swirled in the swirling space, to flow into a minimum passage area part where a refrigerant passage area is most reduced, and to be reduced in pressure. In the gas-liquid mixing state, a gas-phase refrigerant and a liquid-phase refrigerant on a swirling center side are mixed together. With the above configuration, a state of the refrigerant flowing into the minimum passage area part is brought into the gas-liquid mixing state regardless of a change in the outside air temperature to suppress a variation in the refrigerant flow rate flowing out to a downstream side of the depressurizing device.
Further, Patent Document 1 also discloses an ejector using the depressurizing device as a nozzle. The ejector of this type draws a gas-phase refrigerant flowing out of an evaporator due to a suction action of an ejection refrigerant ejected from a nozzle, mixes the ejection refrigerant with the suction refrigerant in a pressure increase part (diffuser portion), thereby being capable of increasing the pressure.
Therefore, in the refrigeration cycle device (hereinafter referred to as “ejector refrigeration cycle”) having the ejector as the refrigerant depressurizing means, a motive power consumption of the compressor can be reduced with the use of the refrigerant pressure increase action in a pressure increase part of the ejector, and a coefficient of performance (COP) of the cycle can be improved more than that of a normal refrigeration cycle device having an expansion valve as the refrigerant depressurizing means.